Question

The natural process by which different groups or communities colonize the same area over a period of time in a definite sequence is called as
A. Adaptation
B. Variation
C. Succession
D. Biological rhythm

Answer 1

Hint: Henry Chandler Cowles, at the University of Chicago, developed the concept of succession. He was inspired by studies of Danish dunes by Eugen Warming. He later on studied the vegetation development on sand dunes on the shores of Lake Michigan.

Complete answer:
Adaptation is the process by which a species becomes fitted to its environment. It occurs due to the result of natural selection’s acting upon heritable variation over several generations. Hence, ‘option A’ is incorrect.
Variation is the difference between groups of organisms of any species. It is caused either by differences in genetic expression or by the effect of environmental factors on the expression of the genetic potentials. Hence, ‘option B’ is incorrect.
Ecological succession refers to the process describing the changes in the structure of a biological community over time. Pioneer species arrive first in a newly created environment. They build a rather simple initial biological community through their interactions with one another.
Biological rhythm is the periodic biological fluctuation in an organism that occurs in response to periodic environmental change. Examples include cyclical variations in the relative position of Earth to the Sun and to the Moon. Hence, ‘option D’ is incorrect.

Hence, the correct answer is option (C).

Note: There are the following types of ecological succession:
-Primary succession occurs in lifeless areas where there is no soil or where the soil is incapable of sustaining life.
-Secondary succession occurs in areas where a biological community has already existed or the community has been removed by small disturbances that did not eliminate all life and nutrients from the environment. It takes place when the primary ecosystem gets destroyed.
-Cyclic succession is only the change in the structure of an ecosystem on a cyclic basis. This drastically changes the structure of an ecosystem.